Step-cut drill bit



v E. WILLIAMS, .n 2,371,490

March 13, 1945;

' STEP CUT DRILL BIT Filed April 10, 1944 I INVENTOR: dWard6fW7fiawgJf I I o I m "m ATTORNEYS.

. of a preceding row; to provide a bit-structure which embeds thecutting elements and formsthe tween the rows of cutting elem ts. "I is distributed through the ports II and extenadmmiaiscsi 4 h I U ITED STATES PATENT arms;

3 ism-gigglin I Edward Wiili ams,Jr. Granville, 'l'ex. Application April 1., 1944, seflll No. 530,251 8 Wins. (01. 25H

V This invention relates to drill bits, particularly teriorly threaded neck for attachment of the those equippedwith cutting elements such asbit toa drillpipe (not shown). j diamonds or the like and has for its principal The body ofthe bit is provided withva'n axial object to provide a drill bit of this character with bore 1 extending inwardly from the neck 6 and a cutting element arrangement which limits the g terminatingshort of the central tip I of the -end depth to which an element can cut when the drill face 3' to provide a suitable'wali thickness 3 for bit is in use. g accommodating a plurality of distribution ports Other objects of the invention are to provide ll having their upper ends connected with thecutting clearance for each row of cuttingclebore 7 and their lower ends extendingfthrough ments; to provide for orientation of the cutting 10 the face I at substantially right angles thereto. elements; in rows wherein each row is set .for- The conical end face 3 and cylindrical face 5 of ward one-half a position so that each row of cutthe body are provided witha plurality of reting elements cuts only one-half the. face cut ceases II for anchoring a matrix material I! wherein the cutting elements are arranged to "cutting faces of thebit as later described. The prevent heating and "stone polishing? when the matrix is a relatively hard, tough material such in before cutting begins. I T i In accomplishing these and other objects, I teriai .enters the recesses and is rigidly anhave provided improved details of structure, the chored so that it forms a permanent andfixed preferred form of which is illustrated in the ac- M f 111 but he m t-"ix is haped o companying drawing wherein: n have a. generally coned end face ll substantially Fig. 1 is a perspective view of a drill bit emso conforming to the cone face 3 and has a pedying the features of the present invention. riphery II curving i t n annular r min Fig.- 2 is a vertical section taken through the 1 f e axis of the bit. Formed inthe tip of the face I and offset Fig. 8 is a plane view of the cutting face of the slightly from the axis of rotation of the bit is a bit. cone-shaped recess ll. Also formed in the face Fig. 4 is a fragmentary. section through one of u s an a ly adially f hthe bit cutters on the line 4-4 of Fig. 3 parinuations l1 0! the ports I. arewater channels. ticularly illustrating the stepped arrangement of w i h n n e r ly thr h h mthe cutting elements and the cutting clearance in: face of the bit and have outlets l9 0 thereof. I p 40 throlllh the annular shoulder 20 formed by the Fig. 5 is a radial section on the line H of matrix material so that a drilling fluid delivered vl lg. 3 particularly illustrating the grooves beugh the drill pipefmot shown) to the bore Fig. 6 is an enlarged section through the tip of sions ll into the watercoursesto wash the cutthe bit particularly illustrating the offset corne 48 tings fliere hrough and upwardly to the top of Referring more in detailto the drawing: the well :as will be understood. One of k l designates a drill bit constructed in accordthe watercourses is also connected with the coneance with the present invention and particularly shaped'rccess It by a groove Ii which provides designed for drilling hard earth formations such an auxiliary course so as to flush the cuttings as chert andthe like. The bit includes a sabtherefrom. stantially cylindrical 1 formed of suitable The V v cutters are formed along the trailmaterial to withstand drilling and is ing edges. of the watercourses and are 01' a suitshaped to provide a slightly'coned end race! rounding as at 4 into a cylindrical side face I. men lormedontheupperendofthebodyisanex-u tingpoints aorientedata-desiiedangleinthe the cutting points of the cutting -of cuttingstepeasbest the cutting elementsin an .each element in face of the formation cut by the cutting elements another and so z. direction of and arranged so that elements in the forward rows are offset slightly from the cutting edges of the succeeding rows to provide a series shown in Fig. 4.

The matrix material I! between each row of cutting elements is sloped upwardly to provide a slight clearance "to avoid heating while the bit. is cutting and to prevent when the drill bit is used in cutting chert' and similar formations, The stepped formation of the rows of cutting elements as shown in Fig. 4 limits the amount of out that can be made by each row oi cutting elements and also provides for better support ofthe elements. This clear ance space connects with water grooves 26 which in turn connect with the watercourses on the respective sides of the cutting ridges of the bit bit rotation so that the cuttings removed by each individual cutting element areueadily cleared and washed to the top of the well.

The face portions ofthe bit on the retractive sides of the cutting ridges are inclined to provide clearance and facilitate removal of the cuttings produced by the hit. As shown in Fig. 3, the cutting ridges have their with diameter of the bit while their trailing edges are substantially paralleland extend substantially tangential with a circle of rotation formed at the center of the bit. The center of the bit surrounding the cone is also oriented with rows elements reduce a stone polishing" Patent is:

forward edges coextensive of diamonds or similar cutting elements spaced by grooves similar 'to the grooves scribed. The rows are arranged e'ccentrlcally with the rotational axis of the bit and the diamonds in one circular-row are onset in the for ward direction relative to the direction of rotation substantially one-half a position relative to adjoining row so that one row cuts only one-half the previously dein a preceding row. This arrangement is preferably maintained throughout the ,cutting surface of the bit: Oil-center is achieved by usin a succession of larger'stones in the inner row sufficient to get a position between the cutting elements of the next row. The rows on the ofiset side are blended into the oflsct rows on the cutters as shown in Fig. 3.

tive in making its own cut in the offset cone. I! is providedon the offset side thereof with a plurality of cutting elements to out the formationand effect reduction thereof at the center of the'bit.

When the bit is in operation, a drilling fluid is circulated through the bore taneously with rotation thereof and jets of drilling fluid are discharged through the ports ll and extensions l'l thereof into the watercourses to wash the cuttings of the bore hole. As the bit is rotated the cutters. are caused to gyrate with respect to the axis of rotation so bit; The bit in operation forms a hole bottom having upwardly sloping portions as shown in Fig. 6 and a central con -like tip is formed'witnin the cone-like recess it of the bit; which tip is being constantly chipped away by re'ason of ec centric mounting elements in the offset side thereof. are flushed from the cone-like recess into the.

'l of thehitsimulas to promotecutting action of -'the.

ridge p rtions. .terme'diate said ridge portions and .face having elements embedded 1 ranged in rows extendin grooves between the rows of diamonds by the 1st discharged through the auxiliary watercourse and through the side of the cone which is connected with the inner end of the opposite watercourse as shown in Figs. 1 and 3. As the rows of cutting formation, the cuttings pass through the clearance spaces into the grooves between the cutting elements and they are discharged from the grooves into watercourses for delivery with the drilling fluid to the top of the bore hole.

From the foregoing it is obvious that I have provided a drill bit ofthe type described wherein the cutting elements are rapid cutting action and the stepped arrangement of the cutting elements limits the amount 1. A drill bitlncluding a body member having 'a drilling face on the end thereof provided with substantially radial ridge portions, said drilling face having an axial portion provided with a recess offset with respect to the member, and cutting elements embedded in said ridge portions including said axial portion and a side of said recess.

2. A drill bit including a drill bit body member having a drilling face provided with substantially radial ridge portions, and cutting elements embedded in said ridge portions and arranged in rows extending transversely of the ridge portions on the respective sides of grooves formed in said ridge portions, said drillin face having watercourses intermediate said ridge portions and connecting said grooves.

3. A drill bit including a drill ber having a drilling tially radial cutting ridge bit body meniportlons, and cutting arranged in stepped rows extending transversely of the ridge portions on the respective sides of grooves formed in said ridge portions, said drilling watercourses intermediate said ridge portions and connecting said grooves.

4. A can hit including a drill bit body meiiiher having a cone-shaped drilling face rovided radial ridge portions, cutting in said ridge portions and arranged in d rows extending transversely of the ridge poitiqnasaid face havingwatercourses intermediate said ridge portions and grooves between said rows of cutting elements, face being provided with arecess with substantially v inaside ofsaid recess.

5. A drill bit including a drill bit body member having a slightly cone-shaped face' providefd with substantially radial ridge portions, and'cutting elements embedded in said ridge portions and arranged in rows extending transversely m. grooves besaid face having-watercourses tween said rows f cutting elements. .fiiA drill bit'including a drill bit body member having .a drilling face provided with substantially'radial cutting ridge portions, and cutting elements embedded in said ridge portions and aransversely of the ridge portio said face he watercourses intermediate saidr168 P rtions-and. g ves beoriented to provide a j' axis of said body face provided with substansaid drilling oilset from the -axial, center thereof andcuttingelements embedded i of the tween said rows-of wam aemma. face being coned and provided with a recess oi!- set from the axial center thereof and having a I groove connecting a pair of said watercourses to flush said recess of cuttings when the bit is in use.

'1. A drill bit including a drill bit body mem-V her having a drilling face provided with substantially radial ridge portions, cutting elements embedded in said ridge portions, said face having watercourses intermediate said ridge portions and provided with a recess oil'set from the axial center thereof and having a groove connecting a pair of said watercourses to flush said recess of cuttings bedded on a side of said recess amino when the bit is in use, and cutting elements em l6 termediate said ridge connecting a pair of said watercourses to 8. A drill bit including a drill bit bodyinernber having a drilling face providedwith substantially radial cutting ridge portions, cutting elements embedded in said ridge portions and arranged in rows extending transversely of the ridge portions, said face having watercourses inportions and grooves between said rows of cutting elements, said drilling face being coned. and provided with a recess oilset from the axial center thereof and having a groove flush said recess of cuttings when the bit is in use, and cutting elements embedded on a side of said WHJLIAMS) Jl. 

